Concrete form construction

ABSTRACT

A concrete from of the type comprising abutting, coplanar panels connected together in edge-to-edge abutting relation to form inner and outer from walls for the pouring of concrete therebetween, the panels being detachably connected together by pivotal latch arms and pins on adjacent panel ends and plural tie rods extending between the inner and outer panels at the junctures of pairs of side-by-side panels. The latch arms and pins are carried on metal straps secured to the outside faces of the panels, the straps being recessed at the panel edges to lie flush with the inner faces of the panels where the tie rods are carried. The tie rods are circular in cross-section and are carried by the recessed strap to break off inside the concrete wall by a single twist at their ends.

United States Patent [1 1 Mikus CONCRETE FORM CONSTRUCTION Glenn H.Mikus, St. Louis, Mo.

[73] Assignee: The fileir icore Co., 111316551105,"

221 Filed: Mar. 29, 1971 211 App]. No.: 128,951

[75] Inventor:

[52] US. Cl 249/192, 249/40, 249/148, 249/190, 249/213 [51] Int. EQ4g9/QQ Primary ExaminerJ. Spencer Overholser Assistant ExaminerDeWalden W.Jones Attorney-Stanley N. Garber 57 ABSTRACT A concrete from of the typecomprising abutting, coplanar panels connected together in edge-to-edgeabutting relation to form inner and outer from walls for the pouring ofconcrete therebetween, the panels being detachably connected together bypivotal latch arms and pins on adjacent panel ends and plural tie rodsextending between the inner and outer panels at the junctures of pairsof side-by-side panels. The latch arms and pins are carried on metalstraps secured to the outside faces of the panels, the straps beingrecessed at the panel edges to lie flush with the inner faces of thepanels where the tie rods are carried. The tie rods are circular incross-section and are carried by the recessed strap to break off insidethe concrete wall by a single twist at their ends.

6 Claims, 5 Drawing Figures Patented Oct. 23,1973

2 Sheets-Sheet i 1 CONCRETE FORM CONSTRUCTION BACKGROUND OF THEINVENTION This invention pertains to concrete forms, and moreparticularly to an improved knock-down'type form for use in the pouringof concrete walls and building foundations.

Certain prior art concrete forms exemplified in US. Pat. Nos. 2,776,464and 2,825,956 have gained wide acceptance and use in the constructionindustry, due primarily to the speed with which they can be erected foruse and dismantled for either storage or use on another project. Typicalof the tie rods or bars used in such forms are those illustrated in US.Pat. No. 2,290,371. These forms generally consist of plural, detachablycoupled, rectangular panels in coplanar abutting edge-to-edgerelationship defining an outer form wall and a similar plurality ofpanels defining an inner form wall, the inner and outer form wallsbeingspaced in parallel planes by the thickness of the concrete wall tobe poured. The panels are detachably joined in endto-end abuttingrelationshipby pivotal levers or latch arms and latch pins carriedat theadjacent ends of the panels. The latch arms and pins are secured toelongate metal straps in turn secured to the outer face of each panel,the panels having notches at their edges under the straps and the strapsbeing slotted to receive the head of the aforementioned tie rods orbars, thereby, upon pivoting of the latch arms over the head of the tiebars and latch pins, joining the side-by-side and inner and outer panelstogether to provide a relatively rigid form construction for theconcrete.

While the prior art forms have gained wide acceptance and use over thepast several years,'there are certain problems and disadvantagesassociated with the use of such forms. For example, the notches in theedges of the panels under the straps fill with concrete which, when set,tends to lock the forms to the concrete wall, rendering it difficult toremove the forms from the completed wall. In addition, the concrete inthe panel notches either adhers to the finished wall formingprotruberances on the wall which must be subsequently removed, or breaksloose from the wall and remains in the notches in the panel requiringcleaning of the panels before they can be used again. Additionally, thetie rods of the prior'art forms are captivated and held against rotationnot only by the notched straps but also by the latch arms. Since thelatch is designed to securely retain the tie rod against rotation,considerable force is required to close the latch over the rod andsubsequently open the latch for removal of the panels. This frequentlyrequires one or more blows from a hammer to accomplish, tending to slowdown the operation and rapidly deteriorating the forms. In addition,since the tie rods are held against rotation by the latch arms they mustfirst be broken by twisting at the latch to permit removal of the panelsand, if a smooth wall is desired, e.g., the interior wall of a basement,they must be again broken slightly inside the wall by twisting afterremoval of the panels.

SUMMARY OF THE INVENTION Accordingly, among the several objects of thepresent invention may be noted the provision of a concrete form havingflat, uninterrupted inner faces for producing a smooth concrete wallthereby eliminating the necessity of manually chipping plural mounds ofconcrete from the face of the completed wall; the provision of such aform which facilitates removal of the form from the completed wall andeliminates removal of concrete from the form prior to its subsequentuse; the provision of a concrete form as above described whichfacilitates latching and unlatching of adjacent side-by-side forms todecrease the time and labor necessary to erect and dismantle such forms;the provision of such a form employing a unique tie bar and tie barretaining mechanism permitting the ends of the tie bar to be broken offinside the completed wall by a single twist of the tie bar end, therebyfacilitating removal of the forms; the provision of a concrete formwhich may be used interchangeably with existing forms and for either theinner or outer form walls; and the provision of such a form which ischaracterized by simplicity of construction, low cost and ease ofoperation and use.

In general, a concrete form assembly constructed in accordance with thepresent invention is comprised of a'plurality of detachably connectedpanels in edge-toedge coplanar abutting relationship defining a firstform wall and a similar plurality of panels spaced laterally from thefirst panels defining a second form wall, with plural tie bars spanningthe first and second walls at the juncture of coplanar panels in thefirst and second walls. Each panel is generally rectangular in shapehaving a recess opening into its abutting end edge for receiving a tierod. Retaining means are provided entending in a common plane with theinner face of the panel from the end of the recess to the end edge ofthe panel for holding the tie rod against lateral movement with respectto the panel. Latch means are provided on the outer face of the panelfor receiving the end of the tie rod and a latch surface on an adjacentpanel to securely hold the panels in edge-to-edge abutting relationship.

Other objects and features will be in part apparent and in part pointedout hereinafter.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of aconcrete form assembly of this invention:

FIG. 2 is an elevation of a portion of the assembly of FIG. 1.;

FIG. 3 is a section taken on line 3-3 of FIG.2.;

FIG. 4 is a section taken on line 4-4 of FIG. 2.;

FIG. 5 is an isolated view ofa tie bar of this invention.

Corresponding reference characters indicate corresponding partsthroughout the several views of the drawings:

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to the drawings,and particularly to FIG. 1, the present concrete form'assembly isindicated generally at 10 as comprising a first or inner form wall 12and a second or outer form 14. Each of the form walls 12 and 14comprises plural, adjacent edge-toedge abutting panels 16A, 16B and 16C,16D. Each panel 16 is of generally rectangular configuration, is of aheight approximately the height of the concrete wall to be built, and isone of a number of standard lengths to form concrete walls of variouslengths. Panels 16 are illustrated as formed of heavy sheet plywood,although other materials, with or without reinforcing upright beams,may-also be used. The panels 16 are notched providing recesses 18 attheir abutting side edges 20 for the passage of a tie rod or bar 22between the inner and outer form walls 12 and 14, as will be more fullydescribed hereinafter. Metal straps 24 are secured to the outer faces ofeach panel 16 by threaded bolts 26, or the like, the latter beingcountersunk so as to lie flush with the inner faces of the panels asshown in FIG. 3. Pivotal latch arms 28 are carried at one edge of eachpanel 16 for captivating tie bars 22 and locking adjacent panels inedgeto-edge abutting relationship, as also will be more fully explainedhereinafter.

As illustrated, plural straps 24 and latching mechanisms 28 may beprovided at spaced vertical intervals along the outer face of the panelsdepending on the height of the panels and the resultant concrete wallsto be built.

In general, the assembly 10, comprised of laterally spaced inner formwall 12 and outer form wall 14, is erected at the site where a concretewall is to be built and is adapted to receive the concrete between theinner faces of the inner and outer form walls. Once the concrete hashardened or set, the forms are removed and may again be used for anotherwall. Clearly, assembly must be sturdy and rigid to adequately supportthe concrete until set. For this purpose, the latch mechanisms 28 areprovided to securely, but detachably, hold adjacent panels 16 incoplanar edge-to-edge abutting relationship, while the tie bars 22 holdthe inner and outer form walls 12 and 14 in laterally spaced, parallelplanes. It will be understood that it is highly desirable to produce asmooth finish on the completed concrete Wall while also reducing costsand labor in erecting and dismantling the form assembly.

As best illustrated in FIG. 24, the present form accomplishes the aboveobjectives by providing an uninterrupted, flush inner form face and animproved tie bar and latching construction. More specifically, theelongate metal strap 24 is secured to and extends along the outer faceof panel 16 with the exception of the edge notched area 18. The notch orrecess 18 extends completely through the panel from its outer to itsinner face and is substantially the same width as the width of metalstrap 24. Notches 18 extend inwardly from both end edges 20 of the panel16 and, as set forth above, receive the ends of tie bars 22. The ends 30of the metal strap 24 are of L-shape in cross-section to conform to theshape of the notch 18 and close the recess at the inner face of thepanel. That is, end portions 30 are provided with a first lateral extent32 extending integrally with strap 24 from the outer face of panel 16 tothe inner face of the panel, and a second longitudinal extend 34extending flush with the inner face of the panel from the inner end ofportion 32 to the edge 20 of the panel. A notch 36, having both ahorizontal and a vertical reach, is provided in strap portion 34 forreceiving tie bar 22.

As set forth above, strap 24 is secured to panel 16 by a plurality ofbolts 26 as shown in FIG. 1. However, at the ends of panel 16 the boltheads, designated 38, are spaced from the strap 24 for pivotalattachment of the latch arm 28 on one end of the panel and for providinga latch pin at the other panel end. Thus, latch arm 28 is pivotallycarried by bolt 38 by an elongate opening 40 for pivotal movement intoand out of locking engagement with bolt 38 on an adjacent panel, thelatter being received by a slot 42 near the end of the latch. The latcharm is also provided with a pair of smaller slots 44 for receiving theend ofa tie bar 22. As shown in FIG. 2, the opening to slot 36 in strapportion 34 is rounded, as at 46, to permit lateral removal of the tiebar if necessary, for example, to install a window frame before pouringthe concrete.

Referring now to FIG. 5, the tie bar 22 comprises an elongate metal barhaving a generally circular crosssection throughout its length.Flattened pairs of ears 48 are formed near the center of the bar forholding the bar against rotation in the wall after the concrete has set.The cars 48 are provided only at the longitudinal edges of the bar topreserve a maximum cross-sectional area at the axis of the bar, henceminimizing the weakening effect of the ears. A shoulder 50 and ashoulder or head 52 are formed in each end of the bar outwardly of ears48. The bar between portions 50 and 52 is received in slot 36 in strapend 34, with portions 50 and 52 retaining the bar against lateralmovement with respect to the panel. Similar pairs of shoulders 54 andheads 56 are formed outwardly of head 52 for captivation of the bar bynotch 44 of latch arm 28. As shown in FIG 2, heads 56 of bar 22 arerectangular providing flat surfaces for gripping with a wrench (notshown) to twist the bar and snap it at score lines 58 slightly insidethe faces of the concrete wall.

Operation is as follows:

To assemble the form walls 12 and 14, the panels 16 in each wall arealigned in edge-to-edge coplanar abutting relationship and the tie barsare positioned such that the bar portions between shoulders 50 and heads52 are in slots 36 of strap portions 34. This is accomplished byseparating the panels sufficiently to insert the tie bars in the openmouth of the slots 36 between the abutting edges of adjacent panels. Itshould be pointed out that since the slotted strap portions 34 areprovided at both end edges of each panel and the latch arms 28 are eachprovided with two bar receiving slots 44, the panels may be useduniversally for either the inner or outer form wall.

After positioning the tie bars 22 in slots 36, thereby securing togetherthe inner and outer form walls 12 and 14, the latch arms 28 are pivoteddownwardly over both the tie bar ends between shoulders 54 and heads 56and the latch pin provided by bolt 38, thereby securely locking togetheradjacent coplanar panels in each form wall. The elongate opening 40 andknife edge lower surface of latch arms 28 facilitates this latchingmovement, and since the tie bars 22 are held laterally by bar portions50 and 52, notches 44 always align with the bar between bar portions 54and 56.

After assembly, the concrete is poured between the inner and outer formwalls and allowed to harden. The form walls are then removed by simplytwisting the heads 56 of the tie bars to cause them to snap at scorelines 58 slightly inside the faces of the completed concrete wall,followed by raising latch arms 28 off of latch pins 38 and tie bars 22.The panels may then be removed for storage or reuse.

In view of the above, it will be seen that the several objects of theinvention are achieved and other advantageous results obtained.

As various changes could be made in the above constructions withoutdeparting from the scope of the invention, it is intended that allmatter contained in the above description or shown in the accompanyingdrawings shall be interpreted as illustrative and not in 8. limitingsense.

I claim:

1. A concrete form comprising a panel of generally rectangularconfiguration having top and bottom edges and first and second sideedges, a cut-out notch in at least one of said side edges between saidtop and bottom edges, said notch extending inwardly from said side edgefrom the outer face of said panel to its inner face, means adapted toreceive and hold a tie bar against lateral movement with respect to saidpanel, said means extending flush with the inner face of said panel insaid notch from the inner end of said notch to the side edge of saidpanel, and latch means on the outer panel face adjacent said side edgenear said tie bar holding means for latching said panel to a similar,abutting panel.

2. A concrete form as set forth in claim 1 wherein said notch and tiebar holding means are provided at both said side edges.

3. A concrete form as set forth in claim 1 wherein said tie bar holdingmeans comprises an elongate metal strap.

4. A concrete form as set forth in claim 3 wherein strap comprises afirst portion extending along and secured to the outer face of saidpanel, a second portion integral with said first portion extending insaid notch from the outer face of the panel to its inner face, and athird portion integral with said second portion extending in said notchflush with the inner face of said panel from said second portion to theside edge of said panel.

5. A concrete form as set forth in claim 4 further comprising a slot insaid third strap portion for receiving said tie bar.

6. A concrete form as set forth in claim 1 wherein said latch meanscomprises a latch arm pivotally carried on the outer face of said panelfor pivotal movement past the side edge of said panel, said arm havingfirst and second slots therein extending from one edge, said slotsrespectively engaging said tie bar and a latch pin on an adjacent panelupon pivoting of said arm.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORECTION Patent: No.3,767,158J Dated October 23, 1973 Inventor(s) G'lenn H. Mikus It iscertified that error appears in the above-identified patent and thatsaid Letters Patent are hereby corrected as shown below:

On the title sheet, delete "[73] Assignee: The Flexicore Co.,

Inc. Dayton, Ohio".

Signed and sealed this 19th day of March 1974.

(SEAL) Attest:

EDWARD M. FLETCHER,JR. c. MARSHALL DANN Attesting Officer I Commissionerof Patents =oRM Po-wso (10-59)

1. A concrete form comprising a panel of generally rectangularconfiguration having top and bottom edges and first and second sideedges, a cut-out notch in at least one of said side edges between saidtop and bottom edges, said notch extending inwardly from said side edgefrom the outer face of said panel to its inner face, means adapted toreceive and hold a tie bar against lateral movement with respect to saidpanel, said means extending flush with the inner face of said panel insaid notch from the inner end of said notch to the side edge of saidpanel, and latch means on the outer panel face adjacent said side edgenear said tie bar holding means for latching said panel to a similar,abutting panel.
 2. A concrete form as set forth in claim 1 wherein saidnotch and tie bar holding means are provided at both said side edges. 3.A concrete form as set forth in claim 1 wherein said tie bar holdingmeans comprises an elongate metal strap.
 4. A concrete form as set forthin claim 3 wherein strap comprises a first portion extending along andsecured to the outer face of said panel, a second portion integral withsaid first portion extending in said notch from the outer face of thepanel to its inner face, and a third portion integral with said secondportion extending in said notch flush with the inner face of said panelfrom said second portion to the side edge of said panel.
 5. A concreteform as set forth in claim 4 further comprising a slot in said thirdstrap portion for receiving said tie bar.
 6. A concrete form as setforth in claim 1 wherein said latch means comprises a latch armpivotally carried on the outer face of said panel for pivotal movementpast the side edge of said panel, said arm having first and second slotstherein extending from one edge, said slots respectively engaging saidtie bar and a latch pin on an adjacent panel upon pivoting of said arm.